Wa'alaikum as'salaam,
I haven't read anything saying men can't use hair products like gel, moose, or hair dryer. However, smart men will not use those and leave fashion alone. Those praducts make your hair follicle weak and lead to baldness.
As for women, they can use makeup to beautify themselves but this is something that should be done where non-mahrams are not able to see them. Which means she can do that at her house or where it's ladies only gathering. A mahram is kin male that you one is not allowed to marry (son, father, grandfather, uncle, etc). Part of command of Allah to cover yourself is conceal your adornments. If hijab covers the body, the face too should be simple looking. how can you hide your adornment and yet beautify your face when going outside.
On a medical side, it's best to limit one self in makeup. It has many side affects because of the chemicals in it.
Ruling on dealing in cosmetics and hairdressers’ supplies
Types of make-up that affect wudoo and ghusl